trFluor™ Eu Acceptor XL665-Streptavidin Conjugate

• Readily used for developing TR-FRET assays
• Conveniently used to bind to a biotinylated probe
• Perfectly paired with an Eu-dye-labeled analyte (e.g., an antibody, or antigen)
• TR-FRET assays have low back ground and high sensitivity

trFluor™ Eu Acceptor XL665-Streptavidin Conjugate is an excellent building block for developing TR-FRET assays. It is labeled with the trFluor™ Eu Acceptor XL665 that is an excellent replacement for the D2 acceptor. The acceptor is commonly used to label antibodies or antigens to prepare the bioconjugates that are used to pair with Eu-labeled probes for developing TR-FRET assays. trFluor™ Eu Acceptor XL665-Streptavidin Conjugate can be readily used with a biotinylated Eu luminescent probe such as antibodies. Eu probes enable time-resolved fluorometry (TRF) for the assays that require high sensitivity. They have large Stokes shifts and extremely long emission half-lives when compared to more traditional fluorophores such as Alexa Fluor or cyanine dyes. Compared to the other TRF compounds, our TR Fluor™ Eu probes have relatively high stability, high emission yield and ability to be linked to biomolecules. The trFluor™ Eu probes are excellent donors for developing TR-FRET assays by pairing with trFluor™ Eu Acceptor XL665-Streptavidin Conjugate. Many biological compounds present in cells, serum or other biological fluids are naturally fluorescent, and thus the use of conventional, prompt fluorophores lead to serious limitations in assay sensitivity due to the high background caused by the autofluorescence of the biological molecules to be assayed. The use of long-lived fluorophores combined with time-resolved detection (a delay between excitation and emission detection) minimizes prompt fluorescence interferences.